RU2803999C1 - Integrated centrifugal blower - flywheel - Google Patents

Abstract

FIELD: internal combustion engines.

SUBSTANCE: invention can be used in forced air exchange systems for internal combustion engines. For an integrated centrifugal supercharger – flywheel (1) for internal combustion engines, blades (2) of the impeller of the supercharger are located directly on flywheel (1) of the engine. Blades (2) can be located on any of the surfaces of flywheel (1). Blades (2) may be built-in elements of flywheel (1) itself. Flywheel casing (3) is at the same time a sealed supercharger housing with a flow channel, a diffuser, a straightening device and corresponding nozzles (9) and (8) for supplying air and discharging injected air to the engine cylinders.

EFFECT: improved operation reliability.

7 cl, 7 dwg

Description

The invention relates to the field of engine building, namely to forced air charging systems for internal combustion engines.

Technical task: improving the functionality of centrifugal superchargers, expanding the range of applications of superchargers, increasing reliability and compactness.

The problem is solved by using an “Integrated centrifugal supercharger - flywheel”, where the supercharger impeller is located directly on the plane of the flywheel or on its end part, or the blades of the supercharger impeller are the stiffening ribs of the flywheel or its damper, and the flywheel casing is a sealed supercharger housing with located in it has a straightening device, a diffuser and an annular air collector.

State of the art.

To increase the power of internal combustion engines without increasing their working volume, air charging systems are used. Air blowers are divided into positive displacement and dynamic. According to the type of drive, blowers are divided into mechanical, i.e. drive superchargers and gas turbines.

A turbocharger is known, consisting of a turbine and compressor parts, where the turbine impeller, spun by the flow of exhaust gases, has a common shaft with the compressor impeller, which in turn pumps air into the combustion chamber of an internal combustion engine (hereinafter referred to as the internal combustion engine).

A turbocharger is a fairly simple design and effective device for increasing the power of an internal combustion engine without increasing the working volume of the cylinders.

Currently, almost all modern diesel engines produced are equipped with a supercharging system with one or more turbochargers.

At the same time, turbochargers have a number of significant disadvantages. The most significant of them is the so-called “turbo lag” or “turbo lag”: the turbocharger lags during sharp acceleration and is ineffective at low and medium engine speeds.

The turbocharger operates in extremely high temperature conditions, which in turn requires the use of heat-resistant materials and high quality workmanship. In addition, the presence of a hot part in the confined space of the engine compartment has a detrimental effect on electrical wiring and rubber products.

The operating speed of rotation of the turbine impeller is in the range of 20-60 thousand rpm, and on some engines reaches 100 thousand rpm, which also requires attention to the quality of materials and manufacturing precision, as well as special conditions for lubrication of rotation units impeller shaft.

The turbocharger shaft bearing is the most thermally stressed engine part.

A mechanical or so-called drive supercharger is known: unlike a turbocharger, drive superchargers do not have a turbine “hot” part and, accordingly, a thermally stressed bearing assembly.

They are divided into volumetric and dynamic.

Volumetric blowers include cam, scroll and vane blowers. The advantage of these types is the linear dependence of the volume of forced air on engine speed, which improves the dynamics at low and medium engine speeds. A significant disadvantage of these types of superchargers is the complexity of manufacturing and the correspondingly high price.

Dynamic superchargers include only centrifugal ones. They are simple in design, do not require expensive materials and high precision manufacturing.

But all driven superchargers have one common drawback, which follows from the name - the supercharger drive. A chain, electric, belt or gear drive means additional friction costs, the need for lubrication and regular maintenance, a complex control system (electric), as well as increased noise and slippage at maximum loads.

A driven centrifugal supercharger also requires a step-up gearbox (multiplier) to increase the angular speed of the supercharger impeller relative to the crankshaft. The disadvantages of this scheme are the large dimensions of the drive and gearbox, an additional lubrication system with high requirements for lubricants, and the difficulty of sealing the gearbox.

A centrifugal supercharger driven by an electric motor requires a high voltage on-board network, a powerful generator, a high-capacity battery and a high-speed electric motor control system.

A centrifugal supercharger driven by an electric motor is used only as an addition to a turbocharger, for operation in transient conditions. Electrically driven superchargers are not used as a permanent source of boost due to significant losses in energy conversion.

The essence of the invention.

“Integrated centrifugal supercharger - flywheel” is distinguished by the fact that the blades of the supercharger impeller are located directly on the flywheel wheel, and the flywheel casing itself is at the same time a sealed supercharger housing with air channels, a diffuser and an annular air collector (scroll) located in it.

This arrangement allows the supercharger to be compactly placed “inside” the internal combustion engine, without “snails” protruding beyond the dimensions. The absence of drive elements simplifies the design, reduces losses, increases reliability and increases the service life of the supercharger.

The flywheel is a very significant part of the internal combustion engine in terms of mass and size; together with the flywheel casing, they occupy a considerable volume of the total size of the internal combustion engine. The dimensions of the casing allow it to accommodate air channels, a straightening device, a diffuser and an annular air collector without noticeable increases in its external dimensions.

The flywheel has a rigid connection with the crankshaft, thereby the speed of rotation of the flywheel is always equal to the speed of rotation of the crankshaft. The flywheel has a high inertial mass and a high angular rotation speed. The large area of the flywheel plane allows large-sized impeller blades to be placed on it, which at low and medium engine speeds are capable of creating high pressure in the intake tract. Moreover, the boost pressure in this case will always be linear to the crankshaft rotation speed.

The operation of the device is as follows:

When the internal combustion engine starts, the flywheel wheel (1) with the supercharger impeller blades located on it (2) begins to rotate. Through the inlet pipe (9) on the flywheel housing (3), air enters the supercharger blades (2) and is thrown back by centrifugal force to the periphery of the impeller, through the diffuser it enters the air channel volute, then through it into the engine intake tract (8).

At idle and low engine speeds, the device maintains the necessary air pressure in the intake manifold. During acceleration, the engine speed and, accordingly, the flywheel increase, the rotation speed of the supercharger blades increases in accordance with the engine speed, increasing the amount of forced air in the intake tract. During a sudden release of gas, the supercharger blades, having no inertia, lose rotation speed along with the flywheel, and accordingly, the crankshaft and do not create excess pressure in the intake tract.

The large size of the impeller blades and the relatively low angular speed of the impeller (compared to a classic centrifugal blower) allows more air to be pumped at a lower flow rate. A lower air flow speed allows you to reduce turbulence and, accordingly, losses due to turbulence and collision of flows.

By creating excess pressure in the enclosed space of the casing, the impeller located on the flywheel creates an elastic load and involuntarily dampens vibrations of the flywheel itself, acting as a torsional vibration damper, which in turn reduces vibration of the engine as a whole.

The advantages of this supercharger include reliability and durability, simplicity of the device, efficiency of supercharging in transient operating modes of the internal combustion engine, absence of losses on the supercharger drive, linear coordination of the boost pressure with engine speed, lack of inertia of the supercharger impeller.

Disadvantages: taking part of the internal combustion engine power to rotate the blades, the need to seal a large flywheel casing, sealing the starter and output shaft, and when used on cars, the difficulty of sealing the manual transmission clutch mechanism or automatic transmission torque converter.

Application area:

First of all, these are internal combustion engines, on which, due to the specific design or operating conditions, it is impossible to install a classic turbocharger, but for which the ratio of specific power per kilogram of weight is extremely important, these are outboard boat engines, motorcycles and mopeds, engines of sports cars and boats, as well as piston engine for light aircraft.

Also, the proposed device can be used as a low-pressure circuit stage for automobile engines with a classic turbocharger: this will increase the efficiency of the turbocharger in transient conditions. On diesel engines with a turbocharger in complex application it will reduce the size of the compressor impeller, accordingly its inertial mass and, as a result, “turbo lag”. All this will improve the dynamic characteristics of commercial vehicles at low and medium speeds, which in turn directly leads to fuel savings and reduced emissions.

Optionally, to increase the efficiency of this type of supercharger, it is possible to use a variable blade pitch device with a centrifugal or hydraulic drive.

The size of the flywheel plate allows the installation of a simple centrifugal device for changing the angle of attack of the blades - a movable spring-loaded load connected to the rotating blade through a screw groove. At low engine speeds, the blades are at the highest possible angle of attack, thereby pumping a large amount of air at low speeds. As the engine speed increases, the speed of rotation of the flywheel increases and, under the influence of centripetal forces, overcoming the resistance force of the springs, the weights move to the outer edge of the flywheel and act through the screw groove on the base of the blades, turning the blades in the direction of decreasing the angle of attack. When the engine speed and, accordingly, the flywheel rotation speed decrease, under the influence of compressed springs the loads return to the lower position and, acting on the blades, set a greater angle of attack. This scheme allows you to more flexibly vary the pressure in the intake tract.

Instead of a centrifugal regulator, it is possible to use a hydraulic drive. The crankshaft has oil channels along its entire length with engine oil under pressure, which is directly dependent on engine speed. On average, the values range from 1 kgf at idle to 5-6 kgf at maximum. The oil channel from the crankshaft is led into the cavity of the flywheel with a plunger located in it, connected to the rotating blades of the compressor impeller.

The system is technically simple to implement, but has a significant drawback - the difficulty of maintaining the tightness of a working fluid such as motor oil, with an operating temperature of 120-130 degrees and under a pressure of 4-5 kgf.

Description of drawings.

Fig 1. - Impeller blades on the flywheel plane (side view)

Fig 2. - Impeller blades on the flywheel plane (view from the front)

Fig. 3. - Flywheel with impeller on a plane in a casing

Fig. 4. - Impeller blades at the end of the flywheel (side view)

Fig. 5. - Impeller blades at the end of the flywheel (front view)

Fig. 6. - Flywheel with an impeller at the end in a casing

Fig. 7. - View of the impeller in the form of stiffening ribs of the flywheel wheel.

Legend:

1. Flywheel

2. Supercharger blades

3. Flywheel-supercharger housing

4. Crankshaft

5. Engine block

6. Unit drive output shaft

7. Output shaft seal

8. Forced air outlet pipe

9. Air supply pipe

10. Crankshaft seal.

Claims (7)

1. Integrated centrifugal supercharger - a flywheel for internal combustion engines, characterized in that the impeller blades of the supercharger impeller are located directly on the engine flywheel, on any of its surfaces, or are built-in elements of the flywheel itself, and the flywheel casing is also a sealed supercharger housing with a flow channel , diffuser, straightening device and corresponding pipes for supplying air and discharging forced air to the cylinders. 2. Integrated centrifugal air blower for internal combustion engines according to claim 1, characterized in that the impeller blades of the impeller are located on the flywheel plane facing the engine. 3. Integrated centrifugal air blower for internal combustion engines according to claim 1, characterized in that the impeller blades of the impeller are located on the flywheel plane facing away from the engine. 4. Integrated centrifugal air blower for internal combustion engines according to claim 1, characterized in that the impeller blades of the impeller are located on the end surface of the flywheel. 5. Integrated centrifugal air blower for internal combustion engines according to claim 1, characterized in that the impeller blades of the impeller are elements of the flywheel itself - its stiffeners or elements of the flywheel damper. 6. Integrated centrifugal air blower for internal combustion engines according to claim 1, characterized in that it has a centrifugal regulator for setting the angle of attack of the impeller blade, which changes the pitch of the blades depending on the angular velocity of the flywheel through the influence of centripetal forces. 7. Integrated centrifugal air blower for internal combustion engines according to claim 1, characterized in that it has a hydraulic regulator for setting the angle of attack of the impeller blades, which changes the pitch of the blades depending on the engine speed and engine oil pressure, with a hydraulic drive from the engine oil lubrication system.